Digest Commentator: David Mackay, MD Student, Cumming School of Medicine Class of 2021, University of Calgary

Digest Editor: 

Jacob E. Berchuck, MD; Craig S. Meyer, PhD, MPH; Ning Zhang, MS; Caroline M. Berchuck, MD; Neil N. Trivedi, MD; Beth Cohen, MD; SunnyWang, MD

Background:

The link between mental and physical health is an important aspect of health outcomes. Numerous studies have explored this fundamental connection. Researchers have long established a relationship between pre-existing mental health disorders and poorer health outcomes. In psychosocial oncology, studies have found higher rates of cancer-related mortality among individuals with pre-existing mental health disorders than in the general population. Lung cancer is the leading cause of cancer related death in Canada and the US. In Canada, in 2020, it was the cause of 1 in 4 cancer related deaths. Roughly half of all lung cancers diagnosed in Canada are diagnosed at stage 4. Non-small cell lung cancer is the most common type of lung cancer diagnosed. Studies have shown that preexisting mental health disorders in patients diagnosed with lung cancer are associated with increased mortality. This study asks the question “Is mental health treatment associated with improved outcomes for people with pre-existing mental health disorders after they are diagnosed with cancer?” It evaluates the association of participation in mental health treatment programs, housing support programs, or employment support programs associated with stage at non-small cell lung cancer diagnosis, receipt of stage-appropriate treatment, and mortality among patients with a pre-existing mental health disorder.

 

Methods:

This retrospective, population-based cohort study looked at data on 55,315 veterans using the Veterans Affairs Central Cancer Registry. This group of veterans all had newly diagnosed non–small cell lung cancer (diagnosed between September 30, 2000, to December 31, 2011). This cohort was separated into three groups: mental health disorder, other mental health disorder, and no mental health disorder. Data were analyzed from January 15, 2017, to March 17, 2020.

Mental health disorders were identified using ICD-9 Codes. To fall in to the mental health disorder category, participants had to have an ICD-9 Code for schizophrenia, bipolar disorder, depressive disorder, anxiety disorder, posttraumatic stress disorder, or substance use disorder linked to their name and listed twice in an outpatient setting or once in an inpatient setting. Researchers also included an other mental health disorder group for participants with diagnoses not specified in the mental health disorder group. These included ICD-9 diagnosis codes 290 to 310 – organic psychotic conditions, other psychoses, neurotic disorders, personality disorders, and other nonpsychotic mental disorders – (except for dementia and tobacco use disorder).

Researchers then determined which participants in the mental health disorder and other mental health disorder groups participated in evidence based programs designed to address mental health needs, substance use, housing and employment needs. Specific programs looked at in this study were mental health intensive case management for schizophrenia and bipolar disorder, psychotherapy for depressive and anxiety disorders, PTSD therapy, and substance use treatment programs. To ascertain participation in these programs, researchers used Current Procedural Terminology codes and Veteran Affairs stop codes (this is a Veteran Affairs coding system used to capture workload data).

As outcome variables, researchers in this study compared (1) the hazard of mortality between patients with individual mental health disorders versus those with no mental health disorder; and (2) patients with individual mental health disorders who participated in evidence-based mental health treatment programs specific to that mental health disorder versus those that did not. Patients with multiple ICD-9 codes associated with their name, and thus multiple mental health disorders, were included in the analysis for each individual mental health disorder.

Results:

Of 55,315 veterans with a new diagnosis of non-small cell lung cancer included in the analysis (98.1% men; mean [SD] age, 68.1 [9.8] years), 18,229 had a preexisting mental health disorder. Patients with any mental health disorder had increased all-cause mortality (adjusted hazard ratio [AHR], 1.03; 95% CI, 1.01-1.06; P = .008) and lung cancer–specific mortality (AHR,1.03; 95% CI, 1.01-1.06; P = .02). Schizophrenia and other mental health disorders were the only individual mental health disorders that were associated with an increased hazard of all-cause mortality (AHRs, 1.09 [95% CI, 1.03-1.16; P = .047] and 1.09 [95% CI, 1.04-1.13; P < .001], respectively) and lung cancer–specific mortality (AHRs, 1.10 [95% CI, 1.02-1.18; P = .01] and 1.07 [95% CI, 1.02-1.13; P = .006], respectively).

Among individuals with both a diagnosis of non-small cell lung cancer and a pre-existing diagnosis of a mental health disorder, participation in mental health treatment programs was associated with a lower likelihood of being diagnosed in a late stage (odds ratio [OR], 0.62; 95%CI, 0.58-0.66; P < .001), a higher likelihood of receiving stage-appropriate treatment (OR, 1.55; 95%CI, 1.26-1.89; P < .001), lower all-cause mortality (AHR, 0.74; 95%CI, 0.72-0.77; P < .001), and lower lung cancer-specific mortality (AHR, 0.77; 95%CI, 0.74-0.80; P < .001). Participation in housing and employment support programs was also associated with similar improvements in all of the outcomes listed above.

Why I Like This Article:

The link between physical and mental health is a fascinating and important one. Systemic hurdles in accessing care and delayed treatment affect mortality outcomes for patients with mental health disorders. This article highlights how mental health support and treatment programs can have a positive impact on health and mortality outcomes for a specific disease.

Evidently, discrepancies in access to mental health resources continue to affect outcomes for patients. This is concerning and an area of research and policy change that I think we will continue to see grow over the coming years. The bottom line of this research is that the association between mental health disorders and an increased risk of mortality due to non-small cell lung cancer is a notable one; participation in programs that support mental health and social needs can improve health outcomes for this group. 

Caution:

The strong association between mental health disorders and increased mortality does not mean that this is the sole, or even the greatest contributing factor.

In this study, multivariate models were adjusted for age, sex, race, marital status, Charlson comorbidity score, smoking status (never, former, or current), substance

use (except for patients with substance use disorder), and year of diagnosis. Understandably, not all variables can be controlled for in this type of research. Factors possibly predictive of outcomes, such as education, socioeconomic status, severity of mental health disorder, and urban vs rural residency were not controlled for.

Of note, the population studied here consists almost entirely of men, so generalization of the results to women is not direct or clear. Patients who participated in mental health treatment programs in this study were younger and had fewer comorbidities. This study also did not include participants who were diagnosed with a mental health disorder after their cancer diagnosis. Finally, treatment outside of the Veterans Health Administration may not have been captured.

Citation of Original Article:

Berchuck JE, Meyer CS, Zhang N, et al. Association of Mental Health Treatment With Outcomes for US Veterans Diagnosed With Non–Small Cell Lung Cancer. JAMA Oncol. 2020;6(7):1055–1062. doi:10.1001/jamaoncol.2020.1466

(https://jamanetwork.com/journals/jamaoncology/article-abstract/2766567)

Other Research Mentioned:

Kisely S, Crowe E, Lawrence D. Cancer-Related Mortality in People With Mental Illness. JAMA Psychiatry. 2013;70(2):209–217. doi:10.1001/jamapsychiatry.2013.278

Canadian Cancer Statistics Advisory Committee. Canadian Cancer Statistics: A 2020 special report on lung cancer. Toronto, ON: Canadian Cancer Society; 2020. Available at: cancer.ca/Canadian-Cancer-Statistics-2020-EN

Arrieta O, Angulo LP, Núñez-Valencia C, et al. Association of Depression and Anxiety on Quality of Life, Treatment Adherence, and Prognosis in Patients with Advanced Non–Small Cell Lung Cancer. Ann Surg Oncol. 2013;20(6):1941-1948. doi:10.1245/s10434-012-2793-5

Lin J, McGlynn KA, Carter CA, et al. The Impact of Preexisting Mental Health Disorders on the Diagnosis, Treatment, and Survival Among Lung Cancer Patients in the US Military Health System. Cancer Epidemiol Biomarkers Prev. 2016;25(12): 1564-1571. doi:10.1158/1055-9965.EPI-16-0316